Closing useless areas with python
If you're using Blender's default startup.blend as your initial starting place, the easier solution would be to change to the "3D View Full screen" layout and then change that area to hold the editor you want (in your case, the UV/Image Editor). The code might look something like this:

bpy.context.window.screen = bpy.data.screens['3D View Full']
bpy.context.screen.areas[0].type = 'IMAGE_EDITOR'